Naveen Kumar ☆ India, 2014-07-23 12:02 (3556 d 16:30 ago) Posting: # 13296 Views: 4,503 |
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Dear All, Please suggest.. The terminal elimination half-life of dutasteride is approximately 5 weeks at steady state. In the available literature studies were crossover, truncated with a washout of 45 days. we are not confident on the wash out as half life much longer. With the above senario, if we go with a parallel design (suggested by FDA guidance 2014) the reported inter subject variability for Dutasteride is > 50 %, resulted sample size is 78 per arm (with 80 % power and 100 % T/R ratio. In above case if we end up with high power for Tamsulosin, is there any chance to make a cut off in sample size for estimation of tamsulosin or else we need to estimate tamsulosin also in all the subjects. Regards, naveen kumar. SR Edit: Category changed. [Helmut] |
Dr_Dan ★★ Germany, 2014-07-23 13:47 (3556 d 14:45 ago) @ Naveen Kumar Posting: # 13297 Views: 2,882 |
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Dear naveen kumar If you draw a blood sample you have to determine the drug concentration and I guess in order to save money you want to avoid this, right? If you exclude a certain number of subjects from sample collection for tamsolusin then you end up in four subject groups (Test and Reference group each devided in A= subjects with samples for dutasteride and samples for tamsolusin and B= subjects with samples for dutasteride and no samples for tamsulosin. The challenge will be the right randomisation, but it should work. However, this must be described in the protocol. Kind regards Dr_Dan — Kind regards and have a nice day Dr_Dan |